New research points to cold January-March

By
Jason Samenow

Predicted winter surface temperature anomalies for the United States Jan-Feb-Mar 2011 in degrees Fahrenheit. Source: National Science Foundation and Judah Cohen, AER Inc.

Andy Revkin of the New York Times posted a fascinating story on his Dot Earth blog today summarizing new research linking fall snow cover in Siberia to winter weather patterns and temperatures over North America and Europe. The research, performed by climate analyst Judah Cohen of Atmospheric and Environmental Research and colleagues at MIT, is funded by the National Science Foundation (NSF). NSF describes the linkage (see this figure for an illustration) accordingly:

When [autumn] snowfall is high in Siberia, the resultant cold air enhances atmospheric disturbances, which propagate into the upper level of the atmosphere, or stratosphere, warming the polar vortex. When the polar vortex warms, the jet stream is pushed south leading to colder winters across the eastern United states and Europe. Conversely, under these conditions the Arctic will have a warmer than average winter.

Based on these relationships, Cohen has developed a seasonal forecast model. In a special report on this work, NSF states that Cohen's model predicts "below normal temperatures for the Eastern U.S." this coming January through March (as shown in the figure above) due to above normal snow cover observed in Siberia during October.

Cohen's model correctly predicted last winter's cold in the Eastern U.S. as well as the cold observed during the winter of 2002-2003 according to NSF. The model has also demonstrated skill in Europe and was "significantly more accurate than [forecasts] issued by the European forecast centers" last winter according to NSF.

The prediction of a cold January through March in the East is at odds with Capital Weather Gang's winter outlook for warmer than average temperatures in January and February in the D.C. metro region. We'll take a closer look Cohen et al.'s research in relation to other seasonal forecasting methodologies in a future post.

Oh thank heavens!!! Bring on the blizzards! Bring on the cold temps! The more cold the better!!!! Now, we just need that southerly storm track to get crankin' again and we may really be in for it! 3 feet, 4 feet, 5 feet; whatever mother nature throws at us, I'm ready!! I NEED snow! Now!!!! Hopefully this ELIMINATES that dreaded, good for nothing, unappreciated rain/snow mix!

Thanks for the feedback. We aim to provide a broad mix of content for a range of audiences - not just technical folks and wonks. I think we provide a lot of "meaty" content but there's also a light, fun side to weather. We'd both narrow our audience and do readers a disservice if we ignored that. Our mission is very clear: provide interesting, entertaining and useful weather content for the consumer of D.C. weather information (irrespective of their technical background).

There is no legitimacy to any specific forecast for snow more than about 5-7 days into the future. Models have essentially no skill beyond that time frame so I'd ignore any references to storms in that time frame.

Jason- Thanks for the polite (for a change from CWG) response. Your mission as described by you (all of you?) is well-stated. You've created a big challenge in achieving the right balance among all audiences. Good luck.

Thanks. It is a challenge, no doubt - but we try our best to offer a good mix. Also, I regret if anyone in the past was impolite to you. That shouldn't happen. I think maybe you're referring to an exchange in a climate change post where there was a misunderstanding that never got smoothed out. Water under the bridge now, but sorry that happened.

@mgg11

The @ symbol has just become a pervasive way of addressing folks in the digital world (e.g. twitter, email addresses, etc).

HEY CWG-- Any way you could do a forecast for Pittsburgh on New Years Day. I am one of many caps fans making the trek up to enemy territory and want to know what the chances are for anti-hockey rain. Thanks!

Yeah HM from AccuWX has been talking about the next 30 days following this weekend to be a stormy period with cold temps. That blizzard hes talking about on the GFS that 300+ hours away is not for the DC metro area. I repeat NOT for our area ;)

Is there something wrong with the weather station in Manassas? It seems like Manassas is always several degrees colder than the rest of us... or are they in some sort of valley that keeps them cooler? Right now, Manassas is in the low twenties while the other suburbs are in the low 30s...

Jason/CWG - This is a very interesting article...thank you. I wonder, when predicting temps after a snowfall, how much does the cool-off come into play in that prediction? I have always wondered why the temps are forecasted higher after a good snowfall than recorded. Also, don't worry about some of the haters on here...some people clearly have too much time on their hands.

I hope CWG is right about the warmer than normal jan/feb. I am so tired of the cold! Enough is enough. We had Jan temps in Dec, so I'm rooting for having all of winter compressed into those awfully cold weeks of Dec!

On this chart/map: as far as can tell, it says Northern Virginia should be 1.0 degree colder than average. Is that really significant? This past weekend it was in the 20s. Other times it's 35. I know if it's on the dreaded snow-rain line it can make a difference, but 1.0 doesnt seem like a lot to get worked up about.

And that line dipping near Florida is 0.1 degree F. Good grief! That matters?

Interesting, central siberia has been a bit above average as far as snowcover goes through Oct/Nov, but Eastern Russia had been running well below normal for that time. I wonder if that might amplify that effect in the model? Though now with record snowfall across much of europe, that effect has probably been negated.

Looking forward to see how you weigh the CWG long range vs. Cohen's. I WAS DEPENDING ON YOURS BEING CORRECT ;-) as I don't like winter. It will be interesting to see what you have to say and how you weigh one against the other. Here is hoping the CWG blows away Cohen!

Kruz, I'm not a seasonal forecaster though occasional for fun, I'll post something on a chat forum. la nina is alive and well but the strongly negative arctic and north atlantic oscillations seems to be trumping la nina climo for temps. When the nao is as strongly negative as its been, it often takes a small respite and then snaps back to more negative values. That suggest after our brief respite temps will fall back to normal to slightly below normal for awhile. If the arctic oscillation eventually switches signs, then we could really warm up. Until then, any warming will probably be transitory. Right now the forecast of the nao and ao are for it to stay negative. P.S. these are my own views not the views of the CWG